Cyclic nucleotides, adenylate cyclase, and cyclic AMP phosphodiesterase in mammary glands from pregnant and lactating mice

Abstract

In the mammary glands of mice, levels of cyclic AMP increased during pregnancy and then fell precipitously following parturition. In contrast, levels of cyclic GMP fell during the gestation period and then rose rapidly during the early days of lactation. Adenylate cyclase and cyclic AMP hohsphodiesterase activities were elevated during the pregnancy and lactation periods.

PIP: Levels of cyclic AMP were determined in mammary gland tissue from pregnant and lactating mice. Levels of cyclic AMP increased during pregnancy and then dropped sharply following parturition. Conversely, cyclic GMP fell during pregnancy and then increased rapidly during the 1st few days of lactation. The activities of adenylate cyclase and cyclic AMP phosphodiesterase were elevated during pregnancy and lactation.